Greatwall is perfectly drinkable, and honestly, I've seen much worse wines in lounges all across the world.
By now, usually they do have cold beer (they do learn
) ready, at least in the lounges it's been a while since I've not had properly cold beer.
Yes, on the flights, quite often the drinks (soft and beer) aren't properly cooled. Not nice, but.. at least even in Y you get a beer.
Compare it to MH / Malaysia, where you won't get even a beer on a flight in Business class (up to 3 hours).. I think TG made their domestic lounges completely dry as well. India? Drinking age in lounges is 25, etc.
Don't compare Chinese domestic flights / Chinese lounge offerings with, say, the Silverkris in SIN or the EK DXB ones... but do compare them with regional ones from similar levels, and you'll be quite pleased in comparison..